Involvement of Non-phosphorylating Glyceraldehyde-3-phosphate Dehydrogenase in the Response to Oxidative Stress

D.M. BUSTOS, C. BUSTAMANTE, A.A. IGLESIAS

JOURNAL OF PLANT PHYSIOLOGY

Elsevier

Año: 2008 vol. 65 p. 456 - 461

0176-1617

SummaryGlyceraldehyde-3-phosphate dehydrogenases catalyze key steps in energy andreducing power partitioning in cells of higher plants. Because non-phosphorylatingglyceraldehyde-3-phosphate dehydrogenase (NP-Ga3PDHase) is involved in theproduction of reductive power (NADPH) in the cytosol, its behavior under oxidativestress conditions was analyzed. The specific activity of the enzyme was found toincrease up to 2-fold after oxidative conditions imposed by methylviologen in wheatand maize seedlings. Under moderate oxidant concentration, lack of mRNA inductionwas observed. The increase in specific activity would thus be a consequence of asignificant stability of NP-Ga3PDHase. Our results suggest that the enzyme could bemodified by oxidation of cysteine residues, but formation of disulfide bridges isdependent on levels of divalent cations and 14-3-3 proteins. The latter differentialeffect could be critical to relatively maintain energy and reductant levels in thecytoplasm of plant cells under oxidative stress.